Nitrous oxide injection systems are known in the art of automobiles for their ability to enhance the power output of internal combustion engines, such as two-stroke, four-stroke, diesel and Wankel rotary engines. Such systems have been used in various applications, including drag racing cars, trucks, motorcycles, snowmobiles, personal watercraft and street vehicles. Nitrous systems have also been used in conjunction with other performance-enhancing devices, such as turbochargers and superchargers.
Known nitrous systems generally operate by introducing a supply of nitrous oxide (chemical formula N20) into the air intake path of the engine combustion chamber of the engine. Nitrous oxide contains about 36% by weight of oxygen whereas air contains only about 21% by weight of oxygen. As such, mixing the oxygen-rich nitrous oxide with the air increases the amount of oxygen available to support the combustion process, and allows a greater amount of fuel to be burned per unit volume of the engine.
The additional fuel required to take full advantage of the use of nitrous oxide may be provided in one of two ways. A first type of system, called a “dry” system, includes a nitrous oxide supply system, and may include various fuel system and/or computer control devices that increase the fuel output of the engine's original fuel delivery system, such as high-flow fuel injectors that replace the engine's stock fuel injectors. Using a dry system, fuel is metered by the engine's regular fuel delivery system (carburetor(s) and/or fuel injector(s)), which may be adjusted or replaced to increase fuel output capacity over that of stock engine fuel delivery components. Dry systems are somewhat limited, however, because they may not be able to introduce enough fuel to react with the oxygen available from high volumes of nitrous oxide. The second type of nitrous delivery system takes advantage of high nitrous oxide flow rates by providing a supplemental fuel delivery system to meter additional fuel to the engine intake path, above and beyond what the original fuel system is capable of delivering. Such systems are called “wet” systems, and typically include a nitrous oxide delivery system as well as a supplemental fuel delivery system that is separate from the engine's original fuel delivery system.
In the descriptions provided herein, the portion of either a wet or dry system that delivers the nitrous oxide is referred to as the “nitrous side” or “nitrous delivery side” of the system, and the portion of a wet system that delivers the fuel is referred to as the “fuel side” or “fuel delivery side.” A typical nitrous side includes: a nitrous supply bottle; a valve to control the nitrous flow; various nitrous oxide supply lines comprising stainless steel or plastic tubing, steel-braided hose or the like; a nitrous delivery device located somewhere in the air inlet path of the engine; and may include a pressure regulator. A typical fuel side comprises: a fuel supply (usually the vehicle's regular fuel tank); a fuel pump; a valve to control the fuel flow; a fuel pressure regulator; various fuel supply lines comprising stainless steel, rubber or plastic tubing, steel-braided hose or the like; and a fuel delivery device located somewhere in the air inlet path of the engine. Typical examples of these and other devices are shown and described in catalogs and websites provided by various companies, such as Holley Performance Products of Bowling Green, Ky., Barry Grant Incorporated of Dahlonega, Ga., and Nitrous Express Inc. of Wichita Falls, Tex., and shown in various patents, such as U.S. Pat. No. 4,494,488 to Wheatley, which is incorporated herein by reference.
Referring to FIG. 1, one particular type of known nitrous plate system 100 uses an adapter plate 102 that fits in the air intake system between the engine's air inlet and the combustion chamber(s). These nitrous systems are often referred to as “plate” systems. The adapter shown in FIG. 1 is intended to be fit between the engine's original carburetor (or throttle-body fuel injector or multipoint fuel injection air valve) and the intake plenum, and generally is intended to achieve broad distribution of oxidizer and fuel into the intake manifold. Such adapters are also known to be placed between different sections of multi-piece intake manifolds. To this end, the plate 102 has one or more central passages 104 with associated perimeter walls 106 shaped to smoothly transition from the carburetor or air valve to the intake manifold, and has four holes 108 through which the original or extended carburetor mounting bolts pass to hold the carburetor and plate 102 in place. Various gaskets (not shown) may be used to create an air-tight seal around the plate 102.
The plate 102 is provided with two spray bars: a nitrous spray bar 110 for delivering nitrous oxide, and a fuel spray bar 112 for delivering fuel. The nitrous spray bar 110 is provided with a number of nitrous delivery orifices 114, and the fuel spray bar 112 is similarly provided with fuel delivery orifices 116. The nitrous and fuel delivery orifices 114, 116 are typically provided at particular angles to obtain optimal mixture of the fuel, nitrous oxide and air. To this end, the spray bars 110, 112 are rigidly fixed within the plate 102 so that they can not rotate out of the preferred orientation. This mounting is shown in FIG. 2, in which the ends of the bars 110, 112 are shown permanently bonded with the plate 102 at their ends by an epoxy bond 118. An interference or press fit may also be used to retain the spray bars. Exemplary delivery orifice outlet orientations are shown in U.S. Pat. Nos. 5,839,418 and 6,279,557, which are incorporated by reference herein. It will also be appreciated that prior art nitrous plates can have additional spray bars, such as shown in U.S. Pat. No. 6,561,172, which is incorporated by reference herein.
The nitrous and fuel spray bars 110, 112 are supplied with their combustion reagents through a nitrous fitting 120 and a fuel fitting 122, respectively. As shown in FIG. 2, the nitrous fitting 120 is received in a threaded hole 124 that abuts an open end of the nitrous spray bar 110. A nitrous hose 126 conveys a supply of compressed nitrous oxide nitrous, and is releasably attached to the nitrous fitting 120 by a threaded fitting 128. A nitrous jet 130 is positioned in the nitrous fitting 120 to meter the amount of nitrous oxide that can pass into the nitrous spray bar 110. This arrangement is similar to the one shown in U.S. Pat. No. 6,691,688, which is incorporated herein by reference. A similar arrangement is provided for the fuel side of the system, with a fuel jet 132 being provided to meter the fuel flow. The nitrous and fuel jets 130, 132 typically comprise a billet-machined part having a precision-made orifice 134 of a specific diameter passing therethrough. The orifice 134 acts as a restriction that limits the fuel or nitrous flow rate for a given pressure.
The jets 130, 132 are selected to match one another and to provide the desired power increase to the engine. For example, if more power is desired, the jets are removed and replaced with jets having larger orifices 134. The limit on power production is often based on either the structural integrity of the engine's “bottom end”—that is, the crankshaft, connecting rods, pistons, writs pins, and webs to which these parts are connected—or the vehicle's ability to transfer the power to the ground, which is dictated by the driveline strength, suspension, tires, track conditions, and other factors. Of course, many other factors, such as the engine head integrity, gasket seal strength, and so on, may ultimately limit the amount of additional power that an engine or vehicle can handle. While some consumers customize various engine and vehicle parts to enhance their engine strength and power transfer capability, others do not. As such, current nitrous plate systems are provided with replaceable jets 130, 132 to allow the end-user to select the appropriate jets for his or her particular application.
While the foregoing nitrous plate systems have provided useful power enhancements to internal combustion engines, there still exists a need to provide improvements in this art. As explained herein, the present inventor has provided various improvements over the prior art, and has discovered certain deficiencies with the prior art and novel and inventive ways to address these deficiencies.